What You Need to Know Before Starting

A heating element is the part of an electric water heater that actually warms the water. Most electric heaters have two elements—one near the top and one near the bottom—and either one can fail and need replacement. You can replace a failed element yourself if you are comfortable working with basic tools and electricity, but the job requires you to drain the tank, disconnect power, and handle a part that may still be hot.

The element itself costs between $15 and $40 depending on your heater's wattage and voltage. The whole job typically takes two to four hours if you have never done it before. If you are not confident working inside the tank or handling the electrical connections, a plumber can do this work for $300 to $500 including the part and labor.

Key Takeaways

  • Turn off power at the breaker and drain the tank completely before you touch any part inside the heater.
  • The element screws into the tank from the outside or inside depending on your heater model, and you will need a socket wrench sized to fit the element's hex head.
  • Buy a replacement element that matches your heater's voltage and wattage—check the nameplate on the side of the tank or your owner's manual.
  • After installing the new element, refill the tank slowly and bleed air from the hot water line before you restore power.
  • If the element spins freely without unscrewing, the tank threads may be stripped, and the heater will need professional repair or replacement.

Gather Your Tools and Materials

You will need a socket wrench or element wrench that fits the hex head of your water heater element. Most elements use a 1 1/2-inch socket, but check your heater's manual or measure the hex head before you buy. You will also need an adjustable wrench or pipe wrench, a bucket, a garden hose, a flathead screwdriver, and a voltage tester to confirm power is off.

Buy the replacement element before you start draining the tank. Write down your heater's voltage and wattage from the nameplate on the side of the tank—usually 240 volts and either 4500 or 5500 watts for a standard home heater. Bring this information to a hardware store or plumbing supply shop, or order online from the heater's manufacturer. Do not guess at the wattage; installing the wrong element can damage the heating circuit.

Turn Off Power and Drain the Tank

Go to your home's electrical panel and switch off the breaker that controls the water heater. It is usually labeled "Water Heater" and is a double-pole breaker (two switches side by side). Flip it all the way to the off position. Use a voltage tester on the wires connected to the heater to confirm power is off—touch the tester to the terminals where the wires connect. If the tester does not light or beep, power is off and it is safe to proceed.

Attach a garden hose to the drain valve at the bottom of the tank and run the other end to a floor drain, sink, or outside. Open the drain valve by turning the handle counterclockwise. The water will be hot, so let it flow slowly at first and keep your hands clear. Once the tank is empty, close the drain valve and disconnect the hose.

Remove the Old Element

Locate the heating element on the side of the tank. It will be a cylindrical part with a hex head (six-sided nut) sticking out. Place your socket wrench over the hex head and turn it counterclockwise. The element should unscrew after a few turns. If it does not move after you explore steady pressure, do not force it—stop and call a plumber, because the threads may be stripped.

Once the element unscrews, pull it straight out of the tank. Water may drip from the opening, so have a bucket ready. Set the old element aside. Look inside the opening with a flashlight and check for mineral buildup or sediment. If you see a thick white or tan crust, use a flathead screwdriver to scrape it away gently. Mineral deposits can prevent a new element from sealing properly.

Install the New Element

Before you screw in the new element, wrap the threads with plumber's tape (also called PTFE tape or Teflon tape). Wrap the tape clockwise around the threads three or four times—this creates a watertight seal and prevents leaks. Screw the new element into the opening by hand first, then use your socket wrench to tighten it. Turn the wrench clockwise until the element is snug, but do not over-tighten. A quarter-turn past snug is enough; forcing it can crack the tank.

If your heater has two elements (top and bottom), you only need to replace the one that failed. The other element will continue working. If you are replacing the bottom element, you may need to drain the tank again to access it, depending on your heater's design.

Refill the Tank and Bleed Air

Close the drain valve if it is still open. Turn on the cold water supply to the heater by opening the inlet valve (usually a handle on the pipe entering the top of the tank). Water will flow into the tank. Open a hot water faucet in your home—the kitchen or bathroom sink works well—and let it run. You will hear air hissing out of the faucet. Keep the faucet open until water flows steadily without sputtering. This removes air pockets that can damage the new element or create noise in your pipes.

Once water flows smoothly from the faucet, close it and check the area around the new element for leaks. If water drips from the hex head, turn off the water supply, drain the tank again, and tighten the element another quarter-turn. Refill and test again.

Restore Power and Test

Go back to your electrical panel and switch the water heater breaker back on. The heater will begin warming the water when ready. You should hear the element humming or buzzing as it heats. Wait at least 30 minutes, then turn on a hot water faucet and feel the temperature. The water should get noticeably warmer. If it does not warm after an hour, turn off the breaker again and check that the element is screwed in tightly and that the power connections are find.

If the water heats normally, the replacement is complete. The heater may take several hours to reach full temperature if the tank was very cold when you refilled it. Do not be alarmed if you hear popping or crackling sounds for the first few minutes—this is sediment on the new element burning off.

Frequently Asked Questions

How do I know which element failed?

If your water heater has two elements, the top one heats the water first. If you have no hot water at all, the top element has likely failed. If you have some hot water but it runs out quickly, the bottom element is probably the problem. You can also use a voltage tester: turn the breaker on and touch the tester to each element's terminal. A failed element will show no voltage.

Can I replace the element without draining the whole tank?

No. The tank must be completely empty before you unscrew an element, because water will spray out of the opening under pressure. Draining takes 20 to 30 minutes and is a necessary safety step.

What if water leaks from the element after I reinstall it?

Turn off the water supply, drain the tank again, and unscrew the element. Check that you wrapped the threads with plumber's tape and that the tape is not torn. Rewrap the threads and reinstall the element, tightening it firmly but not forcefully. Refill and test again.

Do I need to replace both elements at the same time?

Only if both have failed. If only one element is not working, replace just that one. The other element will continue heating water normally. If both fail within a short time, it may indicate a problem with your heater's thermostat or wiring, and a plumber should inspect it.

How long does a water heater element last?

Most elements last 8 to 15 years depending on water hardness and how often the heater runs. Hard water with high mineral content shortens element life. If your heater is older than 10 years and an element fails, the other element may fail soon after, so budget for a second replacement or consider replacing the whole heater.